'\" t
.\" $Id: cdk_button.3,v 1.11 2016/12/11 01:52:43 tom Exp $
.de bP
.IP \(bu 4
..
.de XX
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.TH cdk_button 3
.SH NAME
.XX activateCDKButton
.XX destroyCDKButton
.XX drawCDKButton
.XX eraseCDKButton 
.XX getCDKButtonBox
.XX getCDKButtonMessage
.XX injectCDKButton
.XX moveCDKButton
.XX newCDKButton
.XX positionCDKButton
.XX setCDKButton
.XX setCDKButtonBackgroundAttrib
.XX setCDKButtonBackgroundColor
.XX setCDKButtonBox
.XX setCDKButtonBoxAttribute
.XX setCDKButtonHorizontalChar
.XX setCDKButtonLLChar
.XX setCDKButtonLRChar
.XX setCDKButtonMessage
.XX setCDKButtonULChar
.XX setCDKButtonURChar
.XX setCDKButtonVerticalChar
cdk_button \- create and manage a curses button widget.
.SH SYNOPSIS
.LP
.B cc
.RI "[ " "flag" " \|.\|.\|. ] " "file" " \|.\|.\|."
.B \-lcdk
.RI "[ " "library" " \|.\|.\|. ]"
.LP
#include <cdk.h>

typedef void (*tButtonCallback)(struct SButton *button);
.nf
.TP 15
.B "int activateCDKButton ("
.BI "CDKBUTTON *" "button",
.BI "chtype * " "actions");
.TP 15
.BI "void destroyCDKButton ("
.BI "CDKBUTTON *" "button");
.TP 15
.BI "void drawCDKButton ("
.BI "CDKBUTTON *" "b",
.BI "boolean " "box");
.TP 15
.BI "void eraseCDKButton ("
.BI "CDKBUTTON *" "button");
.TP 15
.BI "boolean getCDKButtonBox ("
.BI "CDKBUTTON *" "b");
.TP 15
.BI "chtype *getCDKButtonMessage ("
.BI "CDKBUTTON *" "b");
.TP 15
.B "int injectCDKButtonbox ("
.BI "CDKBUTTON *" "buttonbox",
.BI "chtype " "input");
.TP 15
.BI "CDKBUTTON *newCDKButton("
.BI "CDKSCREEN *" "cdkscreen",
.BI "int " "xpos",
.BI "int " "ypos",
.BI "const char *" "message",
.BI "tButtonCallback " "callback",
.BI "boolean " "box",
.BI "boolean " "shadow");
.TP 15
.BI "void setCDKButton("
.BI "CDKBUTTON *" "b",
.BI "const char *" "message",
.BI "boolean " "box");
.TP 15
.BI "void setCDKButtonBackgroundAttrib ("
.BI "CDKBUTTON *" "b",
.BI "chtype " "attribute");
.TP 15
.BI "void setCDKButtonBackgroundColor ("
.BI "CDKBUTTON *" "b",
.BI "const char * " "color");
.TP 15
.BI "void setCDKButtonBox ("
.BI "CDKBUTTON *" "button",
.BI "boolean " "box");
.TP 15
.BI "void setCDKButtonBoxAttribute ("
.BI "CDKBUTTON *" "b",
.BI "chtype " "c");
.TP 15
.BI "void setCDKButtonHorizontalChar ("
.BI "CDKBUTTON *" "b",
.BI "chtype " "c");
.TP 15
.BI "void setCDKButtonLLChar ("
.BI "CDKBUTTON *" "b",
.BI "chtype " "c");
.TP 15
.BI "void setCDKButtonLRChar ("
.BI "CDKBUTTON *" "b",
.BI "chtype " "c");
.TP 15
.BI "void setCDKButtonMessage ("
.BI "CDKBUTTON *" "b",
.BI "const char *" "message");
.TP 15
.BI "void setCDKButtonULChar ("
.BI "CDKBUTTON *" "b",
.BI "chtype " "c");
.TP 15
.BI "void setCDKButtonURChar ("
.BI "CDKBUTTON *" "b",
.BI "chtype " "c");
.TP 15
.BI "void setCDKButtonVerticalChar ("
.BI "CDKBUTTON *" "b",
.BI "chtype " "c");
.TP 15
.BI "void moveCDKButton("
.BI "CDKBUTTON *" "b",
.BI "int " "xpos",
.BI "int " "ypos",
.BI "boolean " "relative",
.BI "boolean " "refresh");
.TP 15
.BI "void positionCDKButton ("
.BI "CDKBUTTON *" "b");
.TP 15
.BI "void waitCDKButton ("
.BI "CDKBUTTON *" "button",
.BI "char " "key");
.fi
.SH DESCRIPTION
The Cdk button widget displays a message string and executes a callback when
the user presses enter or space.
As such, it is only useful on a screen
that is being managed by some external screen traversal engine such as
\fBtraverseCDKScreen()\fR.
The button will be highlighted when the widget has the focus.
The following functions create or manipulate the Cdk button widget.
.SH AVAILABLE FUNCTIONS
.TP 5
.B activateCDKButton
activates the button widget and lets the user interact with the widget.
.RS
.bP
The parameter \fBbutton\fR is a pointer to a non-NULL button widget.
.bP
If the \fBactions\fR parameter is passed with a non-NULL value, the characters
in the array will be injected into the widget.
.IP
To activate the widget
interactively pass in a \fINULL\fR pointer for \fBactions\fR.
.RE
.IP
If the character entered
into this widget is \fIRETURN\fR or \fITAB\fR then this function will return a
value from 0 to the number of buttons -1, representing the button selected.
It will also set the widget data \fIexitType\fR to \fIvNORMAL\fR.
.IP
If the
character entered into this widget was \fIESCAPE\fR then the widget will return
a value of -1 and the widget data \fIexitType\fR will be set to
\fIvESCAPE_HIT\fR.
.TP 5
.B destroyCDKButton
removes the widget from the screen and frees up any memory the
object used.
.TP 5
.B drawCDKButton
draws the button widget on the screen.
.IP
If the \fBbox\fR parameter is true, the widget is drawn with a box.
.TP 5
.B eraseCDKButton
removes the widget from the screen.
This does \fINOT\fR destroy the widget.
.TP 5
.B getCDKButtonBox
returns true if the widget will be drawn with a box around it.
.TP 5
.B getCDKButtonMessage
returns the contents of the button widget.
.TP 5
.B injectCDKButton
injects a single character into the widget.
.RS
.bP
The parameter \fBbutton\fR is a pointer to a non-NULL button widget.
.bP
The parameter \fBcharacter\fR is the character to inject into the widget.
.RE
.IP
The return value and side-effect (setting the widget data \fIexitType\fP)
depend upon the injected character:
.RS
.TP
\fIRETURN\fP or \fITAB\fR
this function returns 0, representing the button selected.
The widget data \fIexitType\fR is set to \fIvNORMAL\fR.
.TP
\fIESCAPE\fP
the function returns
-1.
The widget data \fIexitType\fR is set to \fIvESCAPE_HIT\fR.
.TP
Otherwise
unless modified by preprocessing, postprocessing or key bindings,
the function returns
-1.
The widget data \fIexitType\fR is set to \fIvEARLY_EXIT\fR.
.RE
.TP 5
.B moveCDKButton
moves the given widget to the given position.
.RS
.bP
The parameters \fBxpos\fR and \fBypos\fR are the new position of the widget.
.IP
The parameter \fBxpos\fR may be an integer or one of the pre-defined values
\fITOP\fR, \fIBOTTOM\fR, and \fICENTER\fR.
.IP
The parameter \fBypos\fR may be an integer or one of the pre-defined values
\fILEFT\fR, \fIRIGHT\fR, and \fICENTER\fR.
.IP
The parameter \fBrelative\fR states whether
the \fBxpos\fR/\fBypos\fR pair is a relative move or an absolute move.
.IP
For example, if \fBxpos\fR = 1 and \fBypos\fR = 2 and \fBrelative\fR = \fBTRUE\fR,
then the widget would move one row down and two columns right.
If the value of \fBrelative\fR was \fBFALSE\fR then the widget would move to the position (1,2).
.IP
Do not use the values \fITOP\fR, \fIBOTTOM\fR, \fILEFT\fR,
\fIRIGHT\fR, or \fICENTER\fR when \fBrelative\fR = \fITRUE\fR.
(weird things may happen).
.bP
The final parameter \fBrefresh\fR is a boolean value which states
whether the widget will get refreshed after the move.
.RE
.TP 5
.B newCDKButton
creates a pointer to a buttonbox widget.
Parameters:
.RS
.bP
The \fBscreen\fR parameter
is the screen you wish this widget to be placed in.
.bP
\fBxpos\fR
controls the placement of the object along the horizontal axis.
It may be an integer or one of the pre-defined values
\fILEFT\fR, \fIRIGHT\fR, and \fICENTER\fR.
.bP
\fBypos\fR
controls the placement of the object along the vertical axis.
It be an integer or one of the pre-defined values
\fITOP\fR, \fIBOTTOM\fR, and \fICENTER\fR.
.bP
\fBmessage\fR
is the message to display in the button window,
formatted as described in \fIcdk_display\fR.
.bP
\fBcallback\fR
is an optional pointer to a callback function
that will be executed when the user activates the button by pressing space
or enter.
.bP
\fBbox\fR 
is true if the widget should be drawn with a box around it.
.bP
\fBshadow\fR
turns the shadow on or off around this widget.
.RE
.IP
If the widget could not be created then a \fINULL\fR
pointer is returned.
.TP 5
.B positionCDKButton
allows the user to move the widget around the screen via the cursor/keypad keys.
See \fBcdk_position (3)\fR for key bindings.
.TP 5
.B setCDKButton
lets the programmer modify certain elements of an existing
buttonbox widget.
.IP
The parameter names correspond to the same parameter names listed
in the \fBnewCDKButton\fR function.
.TP 5
.B setCDKButtonBackgroundAttrib
sets the background attribute of the widget.
.IP
The parameter \fBattribute\fR is a curses attribute, e.g., A_BOLD.
.TP 5
.B setCDKButtonBackgroundColor
sets the background color of the widget.
.IP
The parameter \fBcolor\fR
is in the format of the Cdk format strings.
(See \fIcdk_display\fR).
.TP 5
.B setCDKButtonBox 
sets true if the widget will be drawn with a box around it.
.TP 5
.B setCDKButtonBoxAttribute
sets the attribute of the box.
.TP 5
.B setCDKButtonHorizontalChar
sets the horizontal drawing character for the box to the given character.
.TP 5
.B setCDKButtonLLChar
sets the lower left hand corner of the widget's box to the given character.
.TP 5
.B setCDKButtonLRChar
sets the lower right hand corner of the widget's box to the given character.
.TP 5
.B setCDKButtonMessage
This sets the contents of the label widget.
.TP 5
.B setCDKButtonULChar
sets the upper left hand corner of the widget's box to the given character.
.TP 5
.B setCDKButtonURChar
sets the upper right hand corner of the widget's box to the given character.
.TP 5
.B setCDKButtonVerticalChar
sets the vertical drawing character for the box to the given character.
.SH BUGS
Changing the Box attribute after the widget has been created probably
does not work right.
None of the positioning/movement code has been tested.
.SH AUTHOR
Grant Edwards, Aspen Research Corporation
.SH SEE ALSO
.BR cdk (3),
.BR cdk_binding (3),
.BR cdk_display (3),
.BR cdk_position (3),
.BR cdk_process (3),
.BR cdk_screen (3),
.BR cdk_traverse (3)